Convert GIFs to XLSX format
I worked for a long time in financial services, and I can tell you that one thing I got sick of hearing was "how do I convert animated GIFs into Excel files". If you're here wondering why nobody has yet exploited this gap in a very lucrative market, wonder no longer. Help is at hand.
- Download the current release binary
- Download your favourite GIF to the same folder
- At a command line in the same folder, type:
gif2xlsx myfavourite.gif(ot whatever you called it)
Animated GIFs are converted on a one-frame-per-worksheet basis, so you have to step through the worksheets to animate them. I was originally intending using conditional formatting and iterative calc to display these, but unfortunately the Excel team* seem to have single-threaded the calculation of conditional formatting and it was far too slow to render.
* I used to work on the Excel team so one could argue that this is partly my fault.
- How does this work?
- It uses Microsoft's OpenXML SDK to generate Excel files and .NET's System.Drawing.Image to create the workbook. As GIF is a colour-indexing format, the program maintains a palette to avoid generating loads of extra formatting records. Because nobody wants their animated spreadsheets to be too large to email to colleagues.
- Why is it so slow?
- The OpenXML SDK isn't all that fast when you write cell values. There are much faster SAX-style ways of writing out spreadsheets using the same SDK but it's harder and I couldn't be bothered. Also, let's be honest, if you've got time to convert GIFs to spreadsheets then you've sure got time to wait for it to finish.
- Why doesn't my GIF scale properly?
- The program scales all GIFs to a fixed size. This could probably be fairly easily fixed but I was really supposed to be working today instead of doing any of this.
- Why does it crash out when given an invalid GIF filename, or when exposed to direct sunlight?
- Because error handling is boring, and when my wife says "what have you been up to today" there needs to be more for me to say than "well, I wrote this converter".
- Why didn't you make this some sort of web service?
- It's on GitHub - be my guest! You are welcome to 100% of the profits.
- Why is your release binary built in debug mode?
- Be grateful for what you have.